Heat exchanger

ABSTRACT

A heat exchanger for exchange between first and second fluids such as motor oil lubricant and liquid coolant in which a baffle sheet of serpentine cross section separates these fluids for heat transfer through the sheet between the fluids, a pair of end plates on opposite ends of the exchanger each having spaced fingers with edge areas joined to the baffle sheet sealing the end spaces between the sides of the folds forming the serpentine section with the end plates being parts of a first enclosing casing for the first fluid and with all seams joining the baffle sheet, first enclosing casing and the end plates being located at the exterior of the heat exchanger for ready inspection of the seams which are preferably formed by brazing and ready accessibility to the seams to make any necessary leakage repairs.

Unite States Patent [i9] ellovary et al.

[54'] HEAT EXCHANGER [75] Inventors: Louis Bellovary; Al 0. Popma, both of Union Grove, Wis.

[73] Assignee: Modine Manufacturing Company,

Racine,Wis.

22 Filed: Feb. 4, 1972 21 Appl. No'.: 223,464

[ 1 3,734,177 1 May 22,1973

Primary Examiner-Charles Sukalo Attorney-Axel A. Hofgren et al.

[57] ABSTRACT A heat exchanger for exchange between first and second fluids such as motor oil lubricant and liquid coolant in which a baffle sheet of serpentine cross section separates these fluids for heat transfer through the sheet between the fluids, a pair of end plates on opposite ends of the exchanger each having spaced fingers with edge areas joined to the baffle sheet sealing the end spaces between the sides of the folds forming the serpentine section with the end plates being parts of a first enclosing casing for the first fluid and with all seams joining the baffle sheet, first enclosing casing and the end plates being located at the exterior of the heat exchanger for ready inspection of the seams which are preferably formed by brazing and ready accessibility to the seams to make any necessary leakage repairs.

10 Claims, 6 Drawing Figures HEAT EXCHANGER BACKGROUND OF THE INVENTION The invention relates to heat exchangers in which two fluids are in contact with the opposite sides of a serpentine plate for transfer of heat from the one fluid to the other through the plate. Ordinarily such exchangers have a casing on one side of the plate for confining one fluid and a second casing on the other side of the plate for confining the second fluid. It is also customary to have joints such as brazed joints for connecting at least one casing and the separator sheetin fluid tight assembly so that there will be no leakage of the fluid.

In most heat exchangers the joint between the separating baffle and the casing is hidden within the exchanger so that not only is the joining such as by brazing difficult but the joint is inaccessible for inspection and for repair in the case of leakage. The heat exchanger of this invention which is disclosed in two embodiments avoids these difficulties by making all joints between the separator plate and the one casing and even between the second casing and the separator plate when two casings are used positioned for ready accessibility from the exterior of the heat exchanger assembly so that joining as by brazing is simple, the joint is open for inspection and where repair is necessary is accessible from the exterior of the exchanger.

The most pertinent prior art of which applicants are aware are U. S. Pat. Nos. 1,367,944; 2,019,351 and 2,576,213. None of these prior art patents, however, have the advantages of the present invention as discussed briefly above and as discussed more fully hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an oil-liquid coolant heat exchanger embodying the invention.

FIG. 2 is an end elevational view of the exchanger of FIG; 1 partially broken away and partially in section for clarity of illustration.

FIG. 3 is an enlarged fragmentary detail section of the embodiment of FIGS. 1 and 2 illustrating the side DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment illustrated in FIGS. 1 and 2 the heat exchanger 10 exchanges heat betweena first fluid which may be engine lubricating oil and a second fluid which may be a liquid coolant for the oil such as water.

The heat exchanger comprises a baffle sheet 11 which may be of aluminum or any heat conducting metal arranged in serpentine section separating the first fluid that is confined by a first casing 12 from the second fluid that is confined by a second casing 13. The baffle sheet 11 which is of serpentine cross section has spaced folds 14 each with spaced apart parallel sides 15 so as to provide side-by-side flow paths for the first and second fluids on opposite sides of the baffle sheet 11.

The opposite ends of the heat exchanger 10 are provided with a pair of end plates 16 of which only one is shown in FIGS. 1 and'2. Each end plate however is substantially identical and each has substantially parallel spaced fingers 17 with edge areas 18 joined to the baffle sheet 11 along seams sealing the end spaces between the spaced sides 15 of the folds as shown most clearly in FIG. 2.

The pair of opposite end plates 16 are parts of the first enclosing casing 12 for the first fluid and with the joined baffle sheet areas and finger areas joined by the seams located at the edge areas 18 being positioned on the exterior of the heat exchanger 10 and at an external side of the assembly of baffle sheet 11, first casing 12 and end plate fingers 17 so that all seams are available from the exterior of the heat exchanger for ready inspection and are accessible from the exterior of the heat exchanger for any necessary leakage repairs as can be easily seen by an inspection of FIGS. 1 and 2.

The second enclosing casing 13 for the second fluid encloses the spaced folds 14 of the baffle sheet 11 and is spaced therefrom as shown in FIG. 2to provide flow paths 19 and side flow paths 20 for the second fluid.

In order to provide for free flow along the sides of the baffle sheet the sides 21 of the second casing 14 are spaced from the sides of the adjacent folds of the baffle sheet 11 by a spacer plate 22 on each side of the sheet 11 as shown at the right side of FIG. 2. This spacing is provided by arranging a plurality of ridges 23 in each spacer plate 22 whose outer ends engage the inner surface of the sides 21 of the casing 13.

In order to increase turbulence and thus improve heat transfer between the first fluid flowing longitudinally of the heat exchanger 10 within the folds 14 in parallel paths each fold is provided on its interior with a pair of turbulator fins 24 with each pair separated by a center metal sheet 25. An example of a suitable turbulator fin is shown in the expanded sheet metal fin of R. S. Johnson US. Pat. No. 3,456,320 assigned to the same assignee as the present application.

In order to provide fluid flow through the heat exchanger the first casing 12 is provided with a pair of access conduits at the opposite ends in the form of threaded fittings 26 and 27. Thus one fitting 26 can provide an inlet for the first fluid such as oil as indicated by the arrow 28 while the other fitting can provide an outlet for the fluid as indicated by the arrow 29.

A very importantfeature of the invention as exemplified in the embodiment of FIGS. 1 and 2 is the locating of the edge area seams at 18 that join the baffle sheet 11 to the casings 12 and 13 on the exterior of the heat exchanger, namely at the opposite ends 16. This exterior location of all joining seams in the assembly of batfle sheet, first casing and end plates, as well as in this embodiment the seam joining the second casing fingers 30 to the baffle sheet on the exterior of the heat exchanger not only permits simple joining of the parts at these seams but also ready inspection from the exterior and simple repair of any leaks that may be formed or that may develop.

In the embodiment of FIGS. 1 and 2 this efficiency of seaming and ease of inspection and repair is also extended to having the side edges 31 of the casing 12, the side edges 32 of the casing 13 and the side edges 33 of the baffle sheet 11 in superimposed relationship and extending the length of the heat exchanger on the exterior thereof.

Thus in the embodiment of FIGS. 1 and 2 every seam joining the parts together is located at an outer surface of the heat exchanger and joining of the parts either by brazing or any other desired method is simple, efficient and readily available for inspection and repair where necessary.

The first embodiment is also provided with inlet 50 and outlet 51 fittings at the opposite ends of the second casing 13 for flow of the second fluid through the heat exchanger countercurrently to the flow of the first fluid as illustrated by the arrows 28 and 29. In the embodiment where the first fluid is engine lubricating oil the second fluid flowing through the casing 13 by way of the fittings 50 and 51 will be a liquid coolant.

In the embodiment of FIGS. 4-6 the heat exchanger 34 is of the plug-in type in which the first enclosing casing for the first fluid, for example lubricating oil, comprises a confining member in the form of a flat plate 35 for the second fluid which for example may be liquid coolant iri a chamber 36. In the illustrated embodiment the chamber wall has an opening 37 across which the plate 35 extends and is attached thereto as by bolts (not shown) extending through openings 38.

The baffle sheet 39 of this embodiment has longitudinally extending and outwardly flaring edge flanges 40 that are attached to the bottom surface of the plate 35. The chamber 36 therefore comprises the second enclosing casing for the first fluid in this embodiment to which the plate 35 is attached.

The baffle sheet 39 of this embodiment is also of serpentine section as shown in FIG. 6 and comprises parallel folds 41 each with parallel sides 42 within which are located turbulator fins 43 similar to the fins 24 of the first embodiment.

In order to close the ends of the folds 41 the heat exchanger 34 is provided with end plates 44 each having an outwardly flaring flange 45 attached to the bottom surface of the plate 35. Each end plate 44 is provided with substantially parallel fingers 46 that are similar to the fingers 17 of the first embodiment and also serving to close the ends of the folds 41. In this embodiment as in the first embodiment when the plug-in heat exchanger 34 is removed from the opening 37 the edge seams 47 joining the end plate fingers 46 and the baffle sheet 39 as well as the seams joining the flanges 40 and 45 to the mounting plate 35 are readily accessible for inspection and for repairs where necessary. In order to provide access and fluid flow through the heat exchanger there is provided as in the first embodiment a pair of oppositely located spaced access conduits in the form of a fitting 48a at one end and a fitting 49a at the other end. Each fitting 48a and 49a is connected to a manifold end 48 and 49, respectively, which spans all of the folds 41 at the two opposite ends of the heat exchanger.

Thus in this embodiment as in the first embodiment the first fluid flows longitudinally between the folds of the baffle sheet by way of end transverse openings 53 and 54. These openings are spaced by the top coplanar strips 60 that interconnect the adjacent folds 41 of the baffle sheet 39. These strips abut the bottom of plate 35 except where they span the access openings 53 and 54. This flow is in heat exchange relationship with the second fluid which in the second embodiment is confined within the chamber 36.

In the process of joining the plate of the second embodiment to the wall of the chamber 36 across the opening 37 as illustrated in FIGS. 4-6 the plate 35 is initially fixed in place by customary spot welds illustrated at 52.

Having described our invention as related to the embodiments shown in the accompanying drawings, it is our intention that the invention be not limited by any of the details of description, unless otherwise specified, but rather be construed broadly within its spirit and scope as set out in the appended claims.

I claim:

1. A heat exchanger for exchange of heat between first and second fluids, comprising: a baffle sheet of serpentine section separating said first and second fluids for heat transfer through the sheet, the sheet having adjacent spaced folds each with spaced apart sides thereby providing side-by-side flow paths for said first and second fluids on opposite sides of said sheet; a pair of end plates on opposite ends of said exchanger each having substantially parallel spaced fingers with edge areas of said fingers joined to said baffle sheet at areas thereof along seams sealing the end spaces between said spaced sides of the folds, said end plates being parts of a first enclosing casing for said first fluid, the baffle sheet areas and first casing fingers areas joined by said seams being located on the exterior of said heat exchanger and at an external side of the assembly of baffle sheet, first casing and end plate fingers for ready inspection of said seams and accessibility for any necessary leakage repairs; a second enclosing casing for said second fluid enclosing said folds of said baffle and spaced therefrom to provide flow paths for said second fluid; and a pair of spaced access conduits to said first enclosing casing for flow of the first fluid through said first casing and within said folds.

2. The heat exchanger of claim 1 wherein there are provided turbulators comprising turbulence producing fins within each of said folds for creating turbulence in the first fluid flowing within said folds.

3. The heat exchanger of claim 1 wherein said first enclosing casing for said first fluid comprises a confining member for said second fluid to which said baffle sheet is attached at the sides thereof.

4. The heat exchanger of claim 3 wherein said confining member comprises a mounting plate to which said baffle sheet is attached, said plate being attachable to a second enclosing casing for said second fluid to extend across an opening therein with said baffle sheet extending into the second casing, the mounting plate and baffle sheet thereby being attachable to and removable from the second casing as a first fluid flow and heat exchange unit.

5. The heat exchanger of claim 4 wherein said mounting plate is provided with spaced fluid flow conduits communicating with the opposite ends of said baffle sheet folds for flow of said first fluid into the folds, in parallel flow within the folds and for flow therefrom.

6. The heat exchanger of claim 1 wherein said pair of end plates on the first enclosing casing cooperate with a similar pair of end plates on a second enclosing casing for said second fluid, the second end plates having similar spaced fingers extending between adjacent folds and sealed thereto along seams that are also located on the exterior of said heat exhanger and externally of the assembly of baffle sheet, second casing and second end casing is provided with longitudinal parallel edges each of which is joined to a corresponding edge of said first casing and to a corresponding edge of said baffle sheet in a single multiple seam on the exterior of said exchanger.

10. The heat exchanger of claim 9 wherein said joined edges project outwardly from said exchanger to provide ready accessibility. 

1. A heat exchanger for exchange of heat between first and second fluids, comprising: a baffle sheet of serpentine section separating said first and second fluids for heat transfer through the sheet, the sheet having adjacent spaced folds each with spaced apart sides thereby providing side-by-side flow paths for said first and second fluids on opposite sides of said sheet; a pair of end plates on opposite ends of said exchanger each having substantially parallel spaced fingers with edge areas of said fingers joined to said baffle sheet at areas thereof along seams sealing the end spaces between said spaced sides of the folds, said end plates being parts of a first enclosing casing for said first fluid, the baffle sheet areas and first casing fingers areas joined by said seams being located on the exterior of said heat exchanger and at an external side of the assembly of baffle sheet, first casing and end plate fingers for ready inspection of said seams and accessibility for any necessary leakage repairs; a second enclosing casing for said second fluid enclosing said folds of said baffle and spaced therefrom to provide flow paths for said second fluid; and a pair of spaced access conduits to said first enclosing casing for flow of the first fluid through said first casing and within said folds.
 2. The heat exchanger of claim 1 wherein there are provided turbulators comprising turbulence producing fins within each of said folds for creating turbulence in the first fluid flowing within said folds.
 3. The heat exchanger of claim 1 wherein said first enclosing casing for said first fluid comprises a confining member for said second fluid to which said baffle sheet is attached at the sides thereof.
 4. The heat exchanger of claim 3 wherein said confining member comprises a mounting plate to which said baffle sheet is attached, said plate being attachable to a second enclosing casing for said second fluid to extend across an opening therein with said baffle sheet extending into the second casing, the mounting plate and baffle sheet thereby being attachable to and removable from the second casing as a first fluid flow and heat exchange unit.
 5. The heat exchanger of claim 4 wherein said mounting plate is provided with spaced fluid flow conduits communicating with the opposite ends of said baffle sheet folds for flow of said first fluid into the folds, in parallel flow within the folds and for flow therefrom.
 6. The heat exchanger of claim 1 wherein said pair of end plates on the first enclosing casing cooperate with a similar pair of end plates on a second enclosing casing for said second fluid, the second end plates having similar spaced fingers extending between adjacent folds and sealed thereto along seams that are also located on the exterior of said heat exhanger and externally of the assembly of baffle sheet, second casing and second end plate fingers for ready inspection of the seams and accessibility for any necessary leakage repairs.
 7. The heat exchanger of claim 6 wherein said fingers of said first and second end plates of said first and second casing are interlaced with said baffle sheet between the interlaced fingers.
 8. The heat exchanger of claim 7 wherein corresponding first and second end plates at the ends of said heat exchanger are substantially coplanar.
 9. The heat exchanger of claim 6 wherein said second casing is provided with longitudinal parallel edges each of which is joined to a corresponding edge of said first casing and to a corresponding edge of said baffle sheet in a single multiple seam on the exterior of said exchanger.
 10. The heat exchanger of claim 9 wherein said joined edges project outwardly from said exchanger to provide ready accessibility. 